/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.test.web.servlet.setup;

import javax.servlet.ServletContext;

import org.springframework.context.ApplicationContext;
import org.springframework.util.Assert;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

/**
 * A concrete implementation of {@link AbstractMockMvcBuilder} that provides
 * the {@link WebApplicationContext} supplied to it as a constructor argument.
 *
 * <p>In addition, if the {@link ServletContext} in the supplied
 * {@code WebApplicationContext} does not contain an entry for the
 * {@link WebApplicationContext#ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE}
 * key, the root {@code WebApplicationContext} will be detected and stored
 * in the {@code ServletContext} under the
 * {@code ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE} key.
 *
 * @author Rossen Stoyanchev
 * @author Rob Winch
 * @author Sam Brannen
 * @since 3.2
 */
public class DefaultMockMvcBuilder extends AbstractMockMvcBuilder<DefaultMockMvcBuilder> {

    private final WebApplicationContext webAppContext;


    /**
     * Protected constructor. Not intended for direct instantiation.
     *
     * @see MockMvcBuilders#webAppContextSetup(WebApplicationContext)
     */
    protected DefaultMockMvcBuilder(WebApplicationContext webAppContext) {
        Assert.notNull(webAppContext, "WebApplicationContext is required");
        Assert.notNull(webAppContext.getServletContext(), "WebApplicationContext must have a ServletContext");
        this.webAppContext = webAppContext;
    }


    @Override
    protected WebApplicationContext initWebAppContext() {
        ServletContext servletContext = this.webAppContext.getServletContext();
        Assert.state(servletContext != null, "No ServletContext");
        ApplicationContext rootWac = WebApplicationContextUtils.getWebApplicationContext(servletContext);

        if (rootWac == null) {
            rootWac = this.webAppContext;
            ApplicationContext parent = this.webAppContext.getParent();
            while (parent != null) {
                if (parent instanceof WebApplicationContext && !(parent.getParent() instanceof WebApplicationContext)) {
                    rootWac = parent;
                    break;
                }
                parent = parent.getParent();
            }
            servletContext.setAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE, rootWac);
        }

        return this.webAppContext;
    }

}
